Whip-stitching device



May 16, 1939- J. T. SANDBERG ET AL 5 3 WHIP-STITCHING DEVICE Filed April10, 1936 5 9 all!!! r 5 INVENTORS JAMES TSANDBEIHG%S'VEN RBJER BUSwlzaw/z. My

ATTORNEY Patented May 16, 1939 siren STATES PATENT OFFICE WHIP- STITCHIN G DEVICE James Torsten Sandberg and Sven Ragnar Bjereus,Stockholm, Sweden Application April 10, 1936, Serial No. 73,750 InSweden April 11, 1935 8 Claims. (01. 112-162) The present inventionrelates to devices for stitching thread carrier and the driving armpoproducing so-called whip-stitching seams, that sition of the apparatusfor the introduction of is, seams comprising usual sewing machine thewhip-stitching thread carrier over and under stitches combined with oneor more whip-stitches the material respectively.

formed by a separate thread overcasting the In Fig. 5 is shown thepositions of the whip- 5 borders of the fabric and attached alternatelyt0 stitching thread carrier and the sewing machine the upper and to thelower threads of the sewneedle in relation to each other and thecarrying ing machine. out of the pressure foot and in this figure is Theprincipal object of the invention is to proschematically shown theposition of the sewing vide a device of this kind either in the form ofan machine threads and the whip-stitching thread 3 appliance to beattached to a sewing machine of in relation to each other when the seamis common type or as a complete whip-stitching formed. sewing machine,permitting in both cases high Fig. 6 is a top plan showing the positionof speed operati'bn such as 3000 stitches per minute, the sewing machinethreads and the whip-stitch- An object of the present invention is toprovide ing threads in relation to each other when the 111 a device formoving in a vertical direction a seam is formed. thread guide forwhip-stitching thread which On the drawing, l shows a horizontal plate,will at all times work over the table of a sewing which supports themachine and which is placed machine or a corresponding plane, so thatthe directly on the sewing machine table 35. This thread guide will bein position alternately over plate I is provided with an extension 50ar- 20 and under the material being worked on. ranged in front of thefeeding mechanism 36.

Another object of the present invention is to From the plate I, avertical plate 2 projects which provide a device by which the strokes ofthe guide principally supports the mechanism belonging to for thewhip-stitching thread can be varied in the device. Two supporting pins 3and 4 are sucha manner that in its upper position the guide arranged inthis plate 2. On the latter pin 4, a 2.1

for the whip-stitching thread does not move so rocking arm 5 ispivotally arranged and provided far over the material as it does in itslowerwith a side arm 6 formed therewith which by position under thematerial. This last mentioned means of a guide opening 7 forms theguiding device is f reat importance for o t in ng a means for a threadcarrier bar 8 which moves su p formation- It operates so at the guidetherethrough and has mounted on one end thereto o t e W pi g thread inits lower p0S of a holder 9 for the whip-stitching thread cartion onreturn obtains a retarded movement in rier in. Arm 5 also is providedwith. an arm I I relation to the needle carryin t h s wi provided withan opening 12. In the opening l2 machine stitches, so that the guide forthe whipi a di 43 provided with thre m; is d stitching thread is notpulled back before the rotatably m unted on said pin 3. said ca dis 3.;Se machine needle has passed through the 48 cooperates with acurve-formed part El armaterial so far in its downward motion that theranged in the part II of the arm 5, in such a whip-stitching thread hasformed the loop round m n r th t h n the cam 48 is m vin in thi thesewing-mach ne St c e case A; revolution round the pin 3, the arm III isThe invention is also characterized by difierent alternately in itsupper and its lower position, so embodiments, ma e evident y thedescription but always positively guided as a consequence of and thedrawin belonging to it. the design of the cam disc 48 and thecurveinvention is illustrated on the accompanyformed parts 5|, :ingdrawing, in w ich g- 1 Shows an pp Pivotally mounted on a pin it on arm5 is 2.

A5 attached to a common sewing-machine. In this bell crank lever l1. Onearm l8 of lever I! has so figure the whip-stitching thread carrier isshown a fork d end connected to a pin 20 m unted on in itsupper-position. a holder IS on the needle bar 2|. By this ar- In F 2 sShown in the like m e the prangement the bell crank lever i'l obtains amovestitching thread carrier in its lower position. ment between twoend-positions as shown in the 5,4) These two figures show the apparatusseen from Figures 1 and 2 (unbroken lines for the lower 5) the front,viz. the apparatus is turned to him, position) in the lower position ofwhich the who uses the machine. needle 22 has penetrated the material.The other Fig. 3 is a top plan of the apparatus, partly in arm 24 of thebell crank lever I7 is directed upsection. wards as the drawing showsand is at its end Fig. 4 shows a diagram concerning the whipprovidedwith a pin 25, which efiects a pivotal 55 connection with the link 26,which in its turn transmits the movement by the pin 21 arranged on onearm 23 of the lever 29, which turns round the pin 4. The movement isfurther transmitted by the lower arm 3c of the lever 29 via the link 32,through the pivotal connection therewith through pin M, to the pin 33arranged on the thread carrier bar ii. The thread carrier bar 8, whichis guided by the opening l, is further guided by moving through a guide34 mounted on plate 2.

The cam disc t8 obtains its intermittent movement (turning) by a toothedwheel M, which also is mounted on the pin 3 and which obtains itsmovement from an arm is which by pin 23 is attached to the arm is, thecam disk being intermittently rocked when the arm 18 is descending.

In the whip-stitching thread carrier is a slot and a loop for the thread38. The thread is kept stretched in a suitable manner by a spring 41with a loop which obtains a rocking moveduring the working of themachine so that the thread is stretched and then slackened in a suitablemanner during the whip-stitching. The thread 35 is guided by a guideloop 35 on its way to the reel of cotton, which is suitably placed on aholder The material which on the drawing is designed by numeral issuitably guided in a side direction by a plate 33 and is kept upliftedover the sewing machine table 35 by means of the extension 5% of plate ithat projects beyond the feeding mechanism The material is pressed downagainst the feeding mechanism by the pressure foot 51 arranged in asuitable manner either at the frame l, 2 or in a common way at theholder for the pressure foot of the sewing-machine.

In Fig. 6 ii and 52 designate the upper and lower loops of the thread 33while 43 and designate the upper and lower threads of thesewing-machine.

In Fi i is schematically shown how the strok s of the whip-stitchingthread carrier can be changed so that the thread c rrier in its lowerposition is moved through a greater distance than in its upper position,the indices 0 and u added to parts it, Hi, l8 and 3B desig nating thepositions of said parts in the upper and lower portion of thewhip-stitching thread carrier. As the pin it is fastened to the arm 55,which pivots around the pin 1, its centre will be displaced during thelowering and lifting move ments of the thread carrier bar as the latteris connected to the arm 5 by means of the side arm Of course thedisplacement of the pin l5 will be smaller than that of a part situatedfarther oil e. g. the slot 52. The arm 38 of the lever 25 will be causedto oscillate with the angles 330 and during the respective changepositions of the pin which in turn causes the different strokes of theneedle bar and thread carrier thereof, as is illustrated in the diagram.

V hat we claim is:

A device for whip-s -tching fabric in combination with an ordinarysewing machine, comprising a frame, a lever turnably mounted on saidframe, a thread carrier mounted on one end of said lever for introducinga continuous thread alternately above below the fabric in back and the;in front of each piercing of the fabric by the needle of the sewingmachine, a cam disk mounted on said frame and driven by the sew machine,arm connected to said lever actuated by said cam disk so as to be movedalternately into an upper and a lower position thereby causing saidthread carrier to be moved alternately above and below the fabric, apivot on said arm, a bell crank lever turnably mounted on said pivot andhaving its one end connected with the needle bar of the sewing machineand its other end connected to the first mentioned lever so as to imparta reciprocating motion to said thread carrier.

2. A device for whip-stitching fabric in combination with an ordinarysewing machine, comprising a frame carrying a pivot, a lever turnablymounted on said frame, a thread carrier mounted on one end of said leverfor introducing a cont nuous thread alternately above and below thefabric in back and then in front of each piercing of said fabric by theneedle of the sewing machine, means for actuating said lever so as toimpart the desired start motion to said thread carrier, comprising a camdisk turnably mounted on said frame and driven by the sewing machine, anarm mounted on said pivot on the frame and connected with said lever,said arm being actuated by said cam disk so as to cause said threadcarrier to be moved alternately into positions above and below thefabric, said cam disk being arranged between the centre line of theneedle of the sewing machine and said pivot.

3. A device for whip-stitching fabric in combination with an ordinarysewing machine, comprising a frame, a lever turnably mounted on saidframe, a thread carrier mounted on one end of said lever for introducinga continuous thread alternately above and below the fabric in back thenin front of each piercing of said fabric by the needle of the sewingmachine, and means for actuating said lever so as to impart the desiredmotion to said thread carrier, comprising a cam disk mounted on theframe and driven by the sewing machine and an arm turnably mounted onthe frame and connected with said lever, said arm having a downwardlyextending portion formed as a guide for said thread carrier, said armeing actuated by said cam disk so as to cause said thread carrier to bemoved alternately into positions above and below the fabric.

4. A device for whip-stitching fabric in combination with an ordinarysewing machine, comprising a frame detachably mounted on the bed of thesewing machine and carrying a pivot, a lever turnably mounted on saidpivot, a thread carrier mounted on one end of said lever for introducinga continuous thread alternately above :l below the fabric in back andthen in front each piercing of the fabric by the needle of the sewingmachine, and means for actuating said lever in order to impart thedesired motion to said thread carrier, comprising a cam disk mounted onframe and driven by the sewing machine, an ar :1 turnably mounted onsaid pivot of the frame and actuated by said cam disk so to be movedalternately into an upper and a lower position thereby causing said t-"ead carrier to be ernately into positions above and be ow the fabric, apivot on said arm, a bell er turnably mounted on said pivot and 5 itsone end pivoted to the needle bar of i s g machine an its other endconnected to sa inst-mentioned lever so as to impart an oscillatingmotion to said lever and thereby a reciprocating motion to said threadcarrier.

5. A device for whip-stitching fabric in combination with an ordinarysewing machine, comprising means for introducing a continuous threadalternately above and below the fabric in back and then in front of eachpiercing of the fabric by the sewing machine needle, and means foractuating said introducing means comprising a cam disk driven by thesewing machine, a pivot, an arm mounted on said pivot and actuated bysaid cam disk so as to cause said introducing means to be moved intoposition alternately above and below the fabric, a lever mounted on saidpivot and connected to said introducing means, and means driven by thesewing machine giving said lever an oscillating motion and thereby saidintroducing means a reciprocating motion.

6. A device for whip-stitching fabric in combination with an ordinarysewing machine, comprising a looper carrying the overcasting thread, abar for supporting said looper, a pivot, an arm mounted on said pivotand connected to said looper bar, a cam disk in engagement with said armand driven by the sewing machine so as to give said looper bar avertical reciprocating motion, a lever mounted on said pivot andconnected to said looper bar, and means driven by the sewing machine soas to give said looper bar an endwise reciprocating motion.

7. A device for whip-stitching fabric in combination with an ordinarysewing machine, comprising a looper carrying the overcasting thread, abar for supporting said looper, a pivot, an arm mounted on said pivotand formed as a guide for said looper bar, a cam disk in engagement withsaid arm and driven by the sewing machine so as to give said looper bara vertical reciprocating motion, a lever mounted on said pivot andconnected to said looper bar, and means driven by the sewing machine soas to give said looper bar an endwise reciprocating motion.

8. A device for Whip-stitching fabric in combination with an ordinarysewing machine comprising a frame, a lever turnably mounted on saidframe, a thread carrier mounted on one end of said lever for introducinga continuous thread alternately above and below the fabric in back andthen in front of each piercing of the fabric by the needle of the sewingmachine, a cam disk mounted on said frame and driven by the sewingmachine, an arm connected to said lever and actuated by said cam disk soas to be moved alternately into an upper and a lower position therebycausing said thread carrier to be moved alternately into positions aboveand below the fabric, a pivot being arranged at such a point on said armthat in its lower position the thread carrier is moved farther inwardsin relation to the fabric than in its upper position, a second leverturnably mounted on said pivot and connected with said first mentionedlever and means driven by said sewing machine giving said second leveran oscillating motion and thereby said thread carrier a reciprocatingmotion.

JAMES TORS'IEN SANDBERG. SVEN RAGNAR BJEREUS.

